1. Field of the Invention
The present invention relates to a communication apparatus that is employed for a multi-media network, etc., and in particular to a communication apparatus that performs the accounting for a communication service for encrypted secret information; and to a communication system that employs such a communication apparatus.
2. Related Background Art
Recently, in consonance with the preparation of optical fiber networks for trunk communication networks, the spread of cable television""systems, the practical use of satellite communications, and the spread of local area networks, there has been an expansion of the so-called information service industry that provides various information, across a communication network, such as images, sounds, and computer data, and charges service fees in consonance with the contents and the amount of the information that is provided. It is important that such services have means to properly account for provided information.
However, in many cases conventional accounting systems are monthly systems, such as those for cable television systems or broadcast satellite systems, that are not concerned with the frequency of service, or accounting systems, such as for computer services, that count only the service frequency (or service time) and that are not concerned with the types or quality of provided information.
It is vitally important that information transmission across a communication network be secure, and various systems for enciphering information and transmitting the enciphered information have been proposed as secure transmission means.
When an information service uses a conventional enciphering system to keep information secret, however, the conventional enciphering system will not be able to cope with the various types of information and services as they continue to expand in the future.
It is assumed that generally an information providing center can provide not only one type of information, but that it can provide an assortment of different types of information. The various types of information differ in their worth, however, and accordingly, conditions wherein the information providing center calculates a charge should be different. From the view of the amount of information that is to be provided, since the quantity of data that is required for an animated image is considerably greater than the data that is required for text information, with an accounting system according to which charges are based on the quantity of information dispensed, a user that received animated image information would have to pay a fee that was a multiple times of the service fee charged for text information. Such an accounting system would be unrealistic.
The conventional accounting system for an information service has the above described problems.
To resolve these problems, it is one object of the present invention to provide an accounting system that can calculates a charge while taking into consideration the types and quality of information and service.
To achieve the object, according to one embodiment of the present invention, provided are encipher transmission means for enciphering data and transmitting enciphered data; counting means for obtaining a count of quantity of data to be enciphered; and accounting means for charging a user for the enciphered data in consonance with a count value held by the counting means.
According to another embodiment, provided are encipher transmission means for enciphering data as units of a block each and for transmitting the enciphered data; counting means for obtaining a count of the blocks to be enciphered; and accounting means for charging a user for the enciphered data in. consonance with a count value held by the counting means.
According to an additional embodiment, provided are encipher transmission means for enciphering data and transmitting enciphered data; counting means for obtaining a count of cryptographic keys that are employed for enciphering; and accounting means for charging a user of the enciphered data in consonance with a count value held by the counting means.
According to a further embodiment, provided are encipher transmission means for enciphering data and transmitting enciphered data while updating a cryptographic key; counting means for obtaining a count of feedback calculations that are performed for updating the cryptographic key; and accounting means for charging a user of the enciphered data in consonance with a count value held by the counting means.
According to still another embodiment, provided is a communication system comprising: a transmission terminal, including encipher transmission means for enciphering data and transmitting enciphered data; and a reception terminal, including encipher reception means for receiving and deciphering enciphered data, the transmission terminal charging the reception terminal a fee that corresponds to an operation of the encipher transmission means.
According to the above described embodiments, the number of calculations that are performed for enciphering, i e., information, such as the quantity of data, the number of cryptographic keys and the number of feedback calculations, is employed to acquire accounting information, so that the information providing center can determine in advance a unit fee in consonance with information type and quality. Therefore, a user can be charged a fair information service fee by the information providing center in consonance with the type, quality and quantity of the provided information.
Further, an information provider can determine a charge for information service in consonance with the quality of information that is provided. Also, since the accounting is performed by the unit, when the provided information differs from the desired information, a user can cancel the request for that information so as to minimize any loss that may be incurred.
A conventional system is not designed to provide a variable enciphering rate for a block signal. As for data in a large quantity, such as image data, for which high speed real-time is required, the conventional system can not provide high-speed cryptographic communication by increasing the enciphering rate for block cryptography even though the security for enciphering is reduced. As for non-real time data in a small quantity, such as text data, the conventional system can not provide secure cryptographic communication by reducing an enciphering rate for block cryptography to increase security.
In addition, a conventional system is not designed to provide a variable key generation rate. Therefore, as for data of high secret for example, the conventional system can not provide high-security cryptographic communication by increasing the key generation rate.
The conventional encipher communication means has the above described problems.
To resolve these problems, it is another object of the present invention to provide an encipher communication apparatus that can vary an enciphering rate, and to provide an enciphering device.
To achieve the above object, according to one embodiment, provided are cryptographic communication means for enciphering transmission data and deciphering received enciphered data and for performing communication; and changing means fort changing a rate that is applied for enciphering/deciphering data.
According to another embodiment, provided are enciphering means for enciphering and deciphering a predetermined algorithm; and changing means for changing a rate for the encipher means without changing the predetermined algorithm.
According to an additional embodiment, provided are enciphering means capable of changing an encipher power relative to transmission data; and changing means for changing the encipher power of the enciphering means in consonance with a deciphering capability of a transmission destination.
According to a further embodiment, provided are enciphering means capable of changing an encipher power relative to transmission data; and changing means for changing the encipher power of the enciphering means by negotiation with a transmission destination.
According to the above embodiments, the enciphering rate and the encipher power can be changed, and the changed enciphering rate or the encipher power that is changed is used in common by a transmitter and a receiver prior to the transmission of an enciphered text. As a result, the selection of the enciphering rate, which conventionally is not taken into account, is possible, and cryptographic communication having a high degree of freedom can be provided.
Further, the enciphering rate for an encipherer and/or the pseudo-random number generation rate are changed, and the changed enciphering rate and pseudo-random number generation rate of the encipherer are employed in common by a transmitter and a receiver prior to the transmission of an enciphered text. As a result, the selection of a trade-off between the security of the enciphering and the processing speed is possible, and cryptographic communication having a high degree of freedom can be provided.
Therefore, even when the processing capability of an encipherer and pseudo-random number generation rates differ from a transmitter and a receiver, cryptographic communication is possible.
It is an additional object of the present invention to provide a service charge system that is consonant with a transfer speed and the security provided for enciphered information.
To achieve the above object, according to one embodiment, provided are encipher transmission means for enciphering data and transmitting enciphered data; selection means for selecting an enciphering rate for the encipher transmission means; and accounting means for charging a fee in consonance with the enciphering rate that is selected by the selection means.
According to another embodiment, provided is a cryptographic communication system, which performs communication of enciphered data across a network and varies an encipher power, wherein a data transmission side charges a data reception side a fee in consonance with the encipher power.
According to the above embodiments, cryptographic communication having a high degree of freedom can be provided by selecting an enciphering rate using the selection means.
Further, an information providing service can be achieved that has a service charge system, which is consonant with encipher power for selected enciphering rates, transfer speeds and security.
Not taken into consideration for conventional cryptographic communication are such adjustments, between an information providing center and a user, as which enciphering system should be employed for providing information, or which mode, or which system for what kind of countermeasure is performed for deciphering, should be employed for cryptographic communication. Particularly not taken into consideration is that an encipher power should be adjusted in consonance with the types of information that are to be exchanged. It is impossible, for example, for data such as image data that are required for a large amount and for high-speed real time, information is provided by an enciphering system at a high processing speed, and for data such as text data that are a small amount at non-real time but are very secret, information is provided by an enciphering system that places a large load on an encipherer but keeps high security.
It is, therefore, difficult to provide a charge system for an information providing service that is consonance with the transfer speed for information providing and the security that is required for communication.
To resolve this problem, it is a further object of the present invention to provide a service charge system that corresponds to a transfer speed and the security for providing enciphered information.
To achieve this object, according to one embodiment, provided are encipher transmission means for enciphering data by using a plurality of enciphering systems and for transmitting enciphered ax data; selection means for selecting one enciphering system from among the plurality of the enciphering systems; and accounting means for charging a fee in consonance with the enciphering system that is selected by the selection means.
According to another embodiment, provided is a cryptographic communication system, which enciphers data across a network and selects an enciphering system, wherein a data transmission side charges a data reception side in consonance with the enciphered system that is selected.
According to the above embodiments, cryptographic communication having a high degree of freedom can be provided by selecting an enciphering system. As a result, an information providing service can be achieved having a service charge system that is consonant with encipher power, transfer speed and security of a selected enciphering system.
It is still another object of the present invention to provide a cryptographic communication apparatus that can select an enciphering system, a cryptographic communication system that employs such an apparatus, and an encipherer.
To achieve the above object, according to one embodiment, provided are a plurality of communication means for enciphering transmission data and deciphering received enciphered data, and for performing communication with each other; and selection means, provided in each of the plurality of communication means, for selecting one of a plurality of enciphering systems.
According to another embodiment, provided are enciphering means for selectively employing a plurality of enciphering systems to encipher information; and mode selection means for selecting an operational mode, the enciphering means selecting one of the plurality of enciphering systems in accordance with the operational mode that is selected.
According to an additional embodiment, provided are enciphering means for selectively employing a plurality of enciphering systems to encipher information; and designation means for designating a security rank, the enciphering means selecting one of the plurality of enciphering systems in accordance with the security rank that is selected.
According to a further embodiment, provided is a cryptographic communication system, which permits a plurality of terminals on a network to communicate enciphered data and selects an enciphering system, wherein when an enciphering system that is designated by a predetermined terminal is to be changed by another terminal, an approval by the predetermined terminal is required.
According to the above embodiments, since selection means for selecting an enciphering system is provided for commutation means that is employed by a transmitter and a receiver that together cryptographic communication, the enciphering system can be arbitrarily set. Further, since the set enciphering system is employed in common by the transmitter and the receiver prior to the transmission of enciphered text, the selection of the enciphering system that conventionally is not taken into consideration is possible, and cryptographic communication having a high degree of freedom can be provided. In addition, an encipher power can be selected.
The other objects and features of the present invention will become readily apparent during the description given while referring to the accompanying drawings.